The Danish government warned Monday of possible attacks on aid workers in the province that has been the scene of a long-running insurgency by separatist rebels, but Van den Berg said U.N. officials believe, “There is no grounds for that at the moment.”

He said a 24-hour ban on U.N. staff driving between provincial capital Banda Aceh and Medan, the largest city on Sumatra island, expired early Tuesday morning and was not extended.

Insisting that aid workers had nothing to fear, rebel leader Tengku Mucksalmina dismissed Indonesian government claims that insurgents might attack relief convoys in hopes of stealing food for their fighters.

“Our mothers, our wives, our children are victims from this tragedy. We would never ambush any convoy with aid for them,” Mucksalmina told The Associated Press from his jungle hideout outside Banda Aceh. “We want them (aid groups) to stay. We ask them not to leave the Acehnese people who are suffering.”

Conference in Kobe
On Tuesday, a U.N. conference on natural disasters opened in Kobe, Japan with hundreds of experts and officials from around the world expected to focus on the creation of a tsunami warning system that could prevent catastrophies stemming from tsunamis.

The Dec. 26 earthquake and tsunami, which claimed at least 162,000 lives in 11 nations, has focused new attention on the a tsunami warning system for the Indian Ocean similar to one on guard for killer waves in the Pacific.

The temporary travel ban between the provincial capital of Banda Aceh and the east Sumatran city of Medan came “strictly because of the fighting going on down there,” said Mans Nyberg, a spokesman for the U.N. High Commissioner for Refugees. “There was reportedly a small battle between the army” and the rebels, Nyberg said. He didn’t know when the battle occurred.

Relief efforts are being led by nearly 15,000 U.S. troops — most of whom are docked off the coast of western Sumatra island. Australia, Singapore, Germany and other nations also have contributed troops.

Indonesian Foreign Ministry spokesman Marty Natalegawa declined to say whether the U.N. precautions were necessary. He said that he could not assess them until he understood the rationale for the Danish warning.

But Mucksalmina said the security warnings were part of an ongoing Indonesian government campaign to discourage foreigners from getting involved because it would bring human rights abuses in Aceh to light.

“The Indonesian military is afraid of foreigners,” the 31-year-old commander said. “They are afraid of greater scrutiny of what’s going on in Aceh.”

Mucksalmina said his forces didn’t need to raid aid convoys because they had purchased a year’s supply of rice, instant noodles and other food before the Dec. 26 tsunami hit.

“We were ready to come down from the mountain to give our supply food, to help clear up the corpses, to help our people,” Mucksalmina said in a rare interview inside a wooden shack, guarded by about 15 fighters with M-16 and Kalashnikov rifles.

“But the military operations continued throughout Dec. 26, 27, 28. On the fourth day, I lost two of my men” in a gunbattle, he said. As he spoke, helicopters continuously buzzed overhead. Some of the rebels ate sticky rice wrapped in banana leaves, and sacks of food and ammunition were piled nearby.

Other governments whose nationals are working in Aceh said they had not upgraded their security warnings in recent days.

Japan’s Foreign Ministry said it had no new information to warrant raising its warning for Indonesia. The German foreign ministry said it had not raised its terror alert, either.

The two countries are among many that included Indonesia on their list of countries where a terrorist threat exists. Jemaah Islamiyah, an Al-Qaida-linked group, is blamed for a series of deadly bombings in Indonesia in recent years, and other radical groups operate in Indonesia.

Indonesian officials regularly blame Free Aceh Movement rebels for shootings and violence in Aceh, even if there is sometimes little evidence of their involvement.

Fears of infiltrationAdding to security concerns has been the appearance of Laskar Mujahidin, an extremist group with alleged links to al-Qaida, which set up a tsunami aid camp in Aceh. The group says it is there only to help tsunami victims.

On Jan. 9, Indonesia warned aid workers that the rebels had infiltrated camps sheltering tsunami survivors, and gunfire was heard near the U.N. compound in Banda Aceh. Before the disaster, foreigners, including aid workers and journalists, had been banned from traveling to Aceh.

Citing the security concerns, Indonesia last week ordered foreigners to outline their travel plans or face expulsion from the region. Hundreds of aid workers have continued to move out into hard-hit areas, despite the restrictions.

Aid groups like Save The Children said late Monday after the U.N. announcement that it hadn’t heard of any new security threats, but would take appropriate measures.

“It would take for us to have to hear something that would be a great security risk for our staff to stop delivering aid, because we know children are in great need,” spokeswoman Eileen Burke said in Banda Aceh.

In other developments:

In Thailand, leaders touring the disaster zone pressed authorities to investigate whether enough had been done to save lives when the killer waves struck. Sweden’s visiting prime minister warned that many European tourists will return to resorts only if their safety is assured.